Means for filtering the fuel supplied to the injector nozzles of internal combustion engines



June 26, 1934. sc RGORODS 1,954,213

MEANS FOR FIL 'I NG T EL SUPPL TO THE INJECTOR NOZZLES INTERN COMBUSTION ENG INES Filed Feb. 20, 1932 2 Sheets-Sheet l J1me 1934- SCHARGORODSKY 64,2 8

MEANS FOR FIL ING THE FUEL SUPPLIED TO THE INJECTOR NOZZLES OF INTERNAL C USTIQN ENGINES I Filed Feb. 1932 2 Sheets-Sheet 2 Patented June 26, 1934 UNITED STATES PATENT oFFIcE MEANS FOR FILTERING THE FUEL SUP- PLIED TO THE INJECTOR NOZZLES OF INTERNAL COMBUSTION ENGINES Application February 20, 1932, Serial No. 594,324 In Germany March 1'7, 1931 8 Claims.

My invention relates to means for filtering the fuel supplied to the injector nozzles of internal combustion engines.

In Diesel engines with airless injection it is known to fit into the conduits serving to conduct the oil fuel to the injector nozzle special filters in order to prevent passage of foreign bodies to the fuel valve. These filters are arranged either in front of or behind the fuel valve in the path of the fuel. In the former case solid particles present in the fuel are liable to deposit under the seat of the valve; in the latter case it is impossible to prevent dirt particles which adhere to the valve or its guide or which are contained in the fuel pump or in the conduits,

whether present in manufacture or passing subsequently with the fuel, from passing to the nozzle or beneath the seat of the valve and thereby rendering impossible the correct functioning at of the nozzle.

The present invention avoids these drawbacks and provides for simplification of the construction by omitting a separate filter member and forming the shank of the valve needle or the wall of the guide passage for the needle as a filter, in which the fuel is forced through narrow slots.

In the accompanying drawings, there is illustrated by way of example in longitudinal section in Fig. 1 a fuel valve according to the invention; Figs. 2 and 3 show the construction of the needle to a larger scale in elevation and in transverse section, respectively. Figs. 4 and 5 are views corresponding to Figs. 1 and 2 showing a modified construction in which the needle shank is stepped and comprises portions of progressively increasing diameter. Fig. 6 is a longitudinal section of a modified fuel valve and Fig. '1 an elevation of the needle thereof on a larger 0 scale. Fig. 8 is a longitudinal section of a further modified construction of valve and Figs. 9 and 10 are, respectively, a longitudinal section and a cross section showing the needle. Figure 11 is a longitudinal sectional view through the valve casing and valve, showing a modification ofmy invention.

The fuel entering at port 1 of the casing a of the fuel valve illustrated in Figs. 1 to 3 passes by way of a passage 2 to an annular recess 3 0 formed in the needle 4, below which are formed spaced longitudinal grooves 5 extending downwardly on the periphery of the needle but closed at their lower ends and alternating with longitudinal grooves 6 closed on top but open at their lower ends near the pointed. end of the needle.

The fuel entering the grooves 5 passes thence to the grooves 6 from which it passes to the needle point. The diameter of the needle through opposed bridge portions or lands 7 between adjacent grooves 5 and 6 is of only slightly less diameter than the internal diameter of the guide passage 8 for the needle; thus affording a filter which retains in the grooves 5 any impurities which might block the valve.

The valve casing a is closed at the lower end by a cap b provided with a nozzle opening and at the opposite end by a cap 0 encasing the spring d acting upon the valve needle 4.

As before remarked, this valve is an injector valve for Diesel engines, the fuel being injected into the cylinder or into a special chamber, in a liquid state. The needle valve is held closed by the spring 11. When fuel under pressure is injected through the port 1 into the passage 2, the pressure against the upper wall of the annular groove 3 will be greater, of course, than the pressure against the lower wall of this annular groove and the liquid will be forced downward through the grooves 5 and 6 and will be discharged into the space below the conical lower end 4 of the valve and the pressure will force the valve upward against the action of the spring (1, injecting the liquid into the cylinder. As soon as the pressure is relieved, the valve will close under the action of the spring d.

In the embodiment shown in Figs. 4 and 5 the shank of the needle 4 is stepped and comprises portions of progressively increasing diameter. Consequently, any solid particles contained in the fuel are retained by the step where the gap between the needle and its guide passage is narrower than the particle diameter. At the last step, which constitutes the finest filter, the fuel passes through connecting channels 10 directly to the needle point. It will be seen that in Figure 4, there are a series of transverse passages formed by the portions 9 of progressively increasing diameter.

As shown in the figures the fuel is not led directly to the needle near its lower end only, as is usual, but is led to the upper portion, whereby better cooling of the needle is effected and the operation of the valve rendered more certain.

ensured because the fuel must fiow along the same paths as in the construction according tn Fins. II and 2. P

- Figs. 8, 9 and 10 show the fuel valve in longitudinal section and the needle itself in elevation and in cross section, to a larger scale, in which the filter portion 13 of the needle is of the same diameter as the stem 14 of the needle. An annular gap 15 for filtration of the fuel is afforded in this case by reason that the bore in the valve casing is of greater cross sectional area than the needle.

In Figure 11, I have shown the guide passage 8 for the needle as being formed with longitudinally extending grooves 5a and 8a and thus it will be seen that it is immaterial whether the guide passage 8 for the needle is smooth and the needle shank provided with grooves or stepped, or

whether the needle shank is smooth and grooves or steps are formed in the wall of the guide passage for the needle as in either case an effective filter for the fuel is provided.

What I claim as my invention and desire to secure by Letters Patent of the United States, is:

1. An injector valve for internal combustion engines of the Diesel type comprising a valve casing having an inlet at one end, and an outlet at the other, a needle valve mounted in the valve casing for reciprocation, a spring holding the needle valve to its seat, the valve when seated closing the outlet from the valve casing, the valve having on its peripheral face a plurality of longitudinally extending channels extending downward from the upper end of the valve and terminating short of the lower end of the valve, and a plurality of channels intermediate the first named channels and extending upward from the lower end of the valve and terminating short of the upper end of the valve, the two series of channels thus overlapping, the lands between said channels being spaced slightly from the confronting surfaces of the casing constituting means obstructing the passage of particles larger than the space between the lands and the casing.

.2. An injector valve for internal combustion engines comprising a valve casing element, a longitudinally reciprocatable needle valve element mounted in the valve casing element, the valve casing element having an inlet adjacent its upper end and an outlet at its lower end, a spring normally urging the valve element to its seat and closing the outlet from the casing, one of said elements having on its face confronting the other element a plurality of longitudinally extending channels opening upon the upper end of the valve but terminating short of the lower end thereof, and a plurality of intermediate channels opening upon and extending upward from the lower end of the valve but terminating short of the upper ends of the first named channel, the lands between said channels being spaced slightly from the surface of the other element and constituting means obstructing the passage of particles larger than the space between the lands and the said surface.

3. An injector valve for internal combustion engines of the Diesel type comprising a valve body having an outlet at its lower end and a central bore, a needle valve shank disposed in said bore and having a conical truncated lower portion, the lower end of the shank below said conical portion being larger in diameter than the outlet, a spring in the valve body normally holding the needle valve shank downward to close the outlet opening in the casing, the needle valve shank having an annular groove in its length and the valve casing having an inlet passage opening into said groove, the valve shank and the wall of the bore between said annular groove and the lower end of the shank being formed to provide a series of fuel passages acting to filter the liquid.

4. An injector valve for internal combustion engines of the Diesel type comprising a valve body having an outlet at its lower end and a central bore, a needle valve shank disposed in said bore and having a conical truncated lower portion, the lower end of the shank being larger diameter than the outlet from the valve body, a spring in the valve body normally holding the needle valve shank downward to close the outlet opening in the casing, the needle valve shank having an annular groove in its length and the valve casing having an inlet passage opening into said groove, the valve shank being formed with a series of longitudinally extending channels opening at their upper ends into said annular groove but terminating short of the lower end of the valve shank and with a series of longitudinal channels opening upon the lower beveled end of the valve shank but terminating short of the upper ends of the first named channels, the lands between said channels being spaced from the surface of the bore.

5. An injector valve for the nozzles of internal combustion engines of the Diesel type comprising a valve body provided with a bore, the bore having an outlet at one end, a needle shank disposed in said bore and having a conical lower portion, the lower end of the shank below the conical portion being larger than and normally closing said outlet, a spring in the valve body urging said shank against its seat, the shank being provided with an annular groove intermediate its length and the valve body having an inlet passage communicating with said groove, two sets of longitudinal grooves constituting fuel channels formed upon the shank, one set of channels opening at their upper ends upon said annular channel and being closed at their lower ends, the other set of channels opening upon the lower conical end of the valve and extendingupward intermediate the first named channels and terminating I fitting closely within the valve casing and below this close fitting portion tapering, the lower end of the shank having a diameter larger than the outlet from the valve casing and normally closing this outlet, the upper portion of the valve shank and the wall of the casing being mutually formed to provide filtering spaces, the lower portion of the shank which closely fits the casing and the wall of the casing confronting this portion being mutually formed to provide ducts communicating each at its lower end with the space below the conical portion of the stem and with the illtration space.

7. An injector valve for internal combustion engines of the Diesel type comprising a valve casing having a cylindrical bore and having an outlet opening at its lower end, a longitudinally reciprocatable needle shank operatively mounted 150 within said bore, the lower portion of the needle shank fitting said bore closely and terminating in a tapering portion and the upper portion of the needle shank fitting the bore closely, the intermediate portion of the needle shank being formed to provide a plurality of filtering spaces between the periphery of the shank and the confronting portion of the wall of the bore,'the casing and the needle shank being formed to provide an inlet communicating with said filtering spaces, the" portion of the valve fitting said bore, the lower portion of the valve also fitting said bore and terminating in a tapering portion, the diameter of the extreme lower end of the valve being greater than the diameter of said outlet opening and normally closing flow therethrough, the valve just below the upper bore fitting portion being formed to provide an annular channel, the valve casing having an inlet port opening into said channel, that portion of the valve below said channel and above the bore fitting portion having a series of portions of progressively increasing diameter toward the lower end of the valve whereby to form a series of filtering spaces progressively decreasing in width toward the lower end of the valve, the

lower portion of the valve which fits the bore closely being formed with ducts communicating between the lowermost filtering space and the tapered lower end of the valve.

LAZAR SCI-IABGORODSKY. 

